Airplane



AUS 6, 1929- yR. F. HALL 1,723,778

AIRPLANE Filed oct. 18, 192e Patented Aug. 6, 1929.

c p UNITED STATES fPA'IENT oFFlcE.

RANDOLPH 1f. HALL, or rrnAcA, miur Yon-x, Assmnon or oNElroUBTn: ToTHEo- Dons r. HALL, or wALLrNGronD, conmacrlcu'r, Am) ONE-FOURTH Toramt.

,WILSOHQ l' ITHAGA, NEW YORK.

Application iled 1,8, '1926. Serial Io. 142,493.

This invention relat to certain improvements in airplanes; and thenature and objects of the invention will be readily recog# nized andunderstood by those skilled in 5 the aeronautical art in the light ofthe fol lowing explanation and detailed description of the accompanyingdrawings what I at present consider to be the preferred embodiments oraerodynamical and mechanical expressions of the invention from amongvarious other forms, arrange ments, combinations and constructions ofwhich the invention is capable within the spirit and scope thereof. Thepresent invention is based on and embodies the broad and basic princiles set forth in and by my United States 'tters Patent No. 1,559,091,dated October 27, 1925, andY is directed to and provides certainiinprovements thereon and to certain modifications Vof the wing or liftsurface designs and arrangements disclosed thereby, with the objects andresults in view of securing an increased performance and operating eiliyciency, as well as certain structural advantages in manufacture and inoperation and use, ofsuch 'types of wings or supporting surfaces.

It has been established that with a wing or lift surface embodyingsuperposed airfoils forming an air displacement passageway therebetween,in accordance with the principles of the invention of my above mentionedpatent, increased eiliciencyand improved performance is possible wlth anenlargement or increase in the depth of the passageway, and an objectand characteristic of the present invention is to provide for anenlarged or increased depth -pasmgewa between the airfoils withoutincrease o? the ,overall or inclusive depth of the wing section andwithout structural complications or material increase in the weight ofthe wifng, while retaining a proper factor of sa e Atyfurthercharacteristic of the invention resides in the design, mounting andoperating arrangements of lateral control surfaces or ailerons for wingsof the types referred' to, with which an increased performance Anothercharacteristic of the invention resides 1n the structural designs andarrangements of the wings'embodying the'afore- With the foregoinggeneral characteris-l tics and objects, as well as certain others inview which will be readily apparent from the following description, theinvention consists in certain no vel features in construction, and inarrangements and combinations of elements, as will be more fully andparticularly referred to and specified hereinafter.v

Referring to the accompanying drawings in which sing;- referenchalracterls1 refer to correspon parts t oug out t e several figuresthereof:

Fig. l, is a transverse sectional view, more or le diagrammatical,`through a wing embodying features of the' invention, and showing thearrangement of fixed lower airfoil with the relatively thinsection upperairfoil and air passageway therebetween, and the vanes or iaps at theforward and rear ends in passageway opening positions, the closedpositions of the ap to convert the wing to a thick section type beingindicated in dotted outline. f

Fig. 2, is a transverse vertical section, more or less diagrammatical,showing another form of wing of the invention, in which ailerons orlateral control surfaces are mounted on the fixed lower airfoil foriiied form of wing in which the forward end and features,

of the -air displacement passageway. is"

formed to open downwardly through the lower or under side of the wingrearwardly from the leading edge, with an arrangement of lower airfoilproviding the vaues or flaps` for opening and closing the passageway,and an operating mechanism therefor.

- A possible embodiment and aerodcal expression of certain features ofthe invention is presented more or less diagrammatically in Fi 1 of theaccompanying/drawings, in w 'ch a win or lift surfaoeis formed of, thespace superposed upper and lower airfoils A and B, respectively, formingthe air displacement passage 10 therebetween, with-the forward vane orap11, and fear Hap 12, for openingtsuchlpassage, or for closing the sameto Vformfjuald convert airfoils A and B into and; `oviding a single wiof the thick secti,v ty

accordance wit vthe principles and. or e?A purposes and results, asfully set forthrandl explained in the hereinbefore referredf'tog U. S.Patent No. 1,559,091.

According to this invention provision made for enlargingior increasingthe depth of the air displacement passage 10, by which a materiallyincreased eiliciency and vim.- proved performance results in theoperation of the wing at high incidence andassagek open condition, butwithout increasingthe overall or inclusive depth of the wing. whenconverted to provide the single section for low incidence, high speedoperation. rlhis is accomplished by forming the up er airf foil A o arelatively thin section t roughout the major portion of its chord, as bya single thickness of metal, plywood, fibre orl the like sheet, althoughin no way so limited, as other constructions and materials can beemployed to secure the desired thin section airfoil. In this manner thepassage 10 between airfoils A and B is enlarged` by increasing its depthwithout affecting the overall or inclusive depth of the complete wing sothat an eficient wing section is pos sible with the passage closed inlow incidence, high speedoperation, while the eiiiciency of the wingwith passage open in high incidence, operation is very materiallyincreased. As further contributing to the eiiiciency of the airdisplacement passage and. ow therethrough, and as a structural factor,the relatively thin upper airfoil of the example hereof, is formed witha nose,

or leading edge section 14y of. substantial thickness, and curvingdownwardly towardv the lower airfoil B. This nose or leading vv,Ty/edgesection 14 decreases in depth or thickness rearwardly to'l and mergeswith Jthe main thin section of airfoil A, and carries macizasl and isdisposed s aced below the-upper air-A l-which islsfe'auredl over.. andacross the up er edges thereof, with the ribs extending orwardly andrearwardly` beyond the lower airfoil ,Bg AA single forward wing beam orlspar 16 is disposed within the leading edge Asection 1 4 of thelupper'airfoil, across and kconnecting the forward ends of the ribs 15,

each rib being formed with a recess 16 to receive the beam 16, as willbe clear by reference to Fig. 3. A longitudinal strip or bar 17 is shownin Fig. 1 in the leading edge section 14', ofv thefupper airfoil A,between 'the ribs 15 for securing theunder covering or lv'skin formingthe surface 14 in position on and to the, nose section 14. The lowerairfoil B is secured to a rear wing beam or spar 18jlat'its'trailingedge, which spar is secured to and'across the lower edges of ribs 15, sothatin effect, the airfoil B and spar 18 togetherp'rovide the rear wingbeam for the structure. The ribs 15 are formed with the lightening holes15 therethrough which also serve and 'function as passages through whichair owing through the displacement passage` 10 may pass, which undercertain conditions ofyaw in wing--operation and Hight may be ofadvantage. If found eX- pedient or necessary the wing structure soformed can be provided with any suitable arrangement of internal bracevwires (not shown) to increase the rigidity and strength I thereof.

The wing thus provides the lspaced upper y and lower airfoils having theair displace-v to position, as shown in dotted lines in Fig. 1, acrossand closing the passage 10, and forming a forward and upwardcontinuation ofthe lower airfoil B, extending to and joining with theunder side of the upper '14 of upper airfoil A that it can be swungairfoil nose `section 14, orcan be swung to the position shown in fulllines in Fig. 1, to

open the passage 10 for air flow therelll through. The forward vane 11is pivotally moimted on.an axis ac ed a distance inwardly or rearwardlom the vane leading edge, sov as to provi ea balanced mounting thereforto assist in swinging .thevleading edge of the vane downwar toopenposition, and upwardly toc osed position, against the airflow,although the invention is not limited to such mounting. The wing ribs 15are cut away rearwardly and upwardly from the pivotal axis 11', of vane11 to provide the recesses 19 to receive and permit the rear or trailingportion of the vane to swing upwardly in passage opening jpositioii, asclearly shown in Figs. 1, and 3 of the drawings.

' A rear flap 12 is mounted pi'votally along the trailing edge of lowerairfoil-B at the rear`\wing beam 18, and in the example here-A ofextends 'rearwardly from and as a continuation-and'part of the lowerairfoil, to and terminating at its trailingedge sub stantially beneathand in line with the trailing edge Aof the upper airfoil A. The rearflap 12is swingable downwardly to the position shown in full lines inFig. 1 to open the'passage 10, which is continued between the flap.12and upper .airoil A to discharge between the spaced trailing edgesthereof;

n and is swingable upwardly,to position across vand closing theassage10, as shown in dotted outline in ig. 1. Y In the passage closingposition the rear flap 12 is raised to form a continuation of lowerairfoil B, joining and merging at its trailing edge with the trailingedge of the upper airfoil, and with forward vane 11 in closed positionforms or converts the spaced airfoils A and B into a single airfoil orwing of the thick section type; A lateral control surface or aileron 20is in the/present instance pivotally mounted at the desired location onand from the rear flap 12 andmovable therewith so as to be operable andeiectiveY for control of the wing with the flap closed or open. Anysuitable or desired operating mechanism (not shown) is provided foropening and closing the forward vane A11 and rear flap, operating toeither simultaneouslyo 11 and close the same or permit of their beinglindependently operated.

, With the wing of tion under high 'incidenceA and low speed conditions,forward vane-`11 and rear flap -12 are swung to -open positions whichresults in displacement of air rearwardly and downwardly through assage10 and a material increase in the li of the wing, as well 'as increasingthe criticaln angle of the wing, with the various advantages and resultsderived thereby, as will be understood by those skilled in this art.Under low incidence and high speed flight operation, forward vane 11.andrear flap 12 are swung to closed positions and the wing is convertedtime Fig. lin flight opera-l to a single relativel thick section type'having a section and c aracteristics to develop an eiiicient lift/ dragvalue. structurally the win -design'of Fig. 1 is simple and of relativey light weight, enabling practical low cost production, while inoperation and use the construction is such that internal inspection oithe wing can be readily madevat any One of the Hight characteristics ofthe design and construction of the wing of 'Ill Fig. l, is a slightmovement of the center of pressure when the passage 10 is open o rclosed by the flaps 11 and 12, which is of advantage structurally aswell as aerodynamically. The wing of Fig. 1 inthe stalling or spinning.condition is'very'efficient as .a biplane, due tothe design andarrangement thereof, as described.

A lateral control surface or aileron mounting for a wing of the t pe ofFig. 1, is more or less diagrammaticall illustrated in Fig. 2 of thedrawings, by'wlirich the general performance and efiiciency of the wingis increased, and the control thereor` rendered more positive andresponsive. The wing consists ofthe thin section upper airfoil A withthe lower airfoil B having the passage Y 10 therebetween controlled byvane 11 and flap 12, 'as previously describedl with reference to Fig. 1.The rear flap 12 terminates a distance inwardly from the wing tip, and

the chord of the lower fixed airfoil B is increased rearwardly to formthe extension B thereof between wing flap 12 and the wing tip, as willbe clear by reference to Fig. 2. The leading edge construction withtherforwardend of passage 10 and forward vane 1 1 is extended outwardlya distance across the lower airfoil B'and the rearward extension B sothat thewpassage 10 extends over a portion of lower airfoil B-4B.

'A lateral control surface or aileron`21is`- disposed to the rear ofandin substantial continuation of the lower airfoil extension B',between the outer end of rear flapv 12 and the wing tip, and extendsvrearwardly to the wing trailing edge.

The aileron 21 is preferably, although' not so limited, of the so-calledbalanced type, which in the present example is secured by pivotallymounting the aileron for vertically swinging movement on an axis 22spaced a distance rearwardly y tance inwardly from the trailing edgethere-` of, above the aileron 21, and terminating at approximately kthevertical plane of the ailef ron -pivot or axis 22, Yso that with theaileron in normal inoperative position forming a trailing portion ofairfoil extension B',

gap or passage 23 is provided between the aileron and airfoil Ainrearward continuathe wing. The

positlon opening passage 10, upward inovcment of. aileron 21 tends toclose or decrease the gap r outlet'23 from'passage l0, and thusdecreases the lift and increases the drag on the proper wing withcorresponding increase vin the control action and e'ect of the aileron,while downward movement of 'the aileron 21 tends to increase gap 23 andthe discharge opening from passage 10 and thereby properly decrease thedrag with increase in the lift.V The aileron mounting as shown increasesthe lift of the aileron por-V tion of the wing and hence increases thetotal lift developed by the wing, and with the increased lateral controletliciency, very materially contributes to increased wing performanceand eiiiciency. With the wing disclosed in a stall, when most required,the aileron and control response therefrom is very effective, and thiseffectiveness is further iinyproved and the lift ofi the wing increasedwith the forward vane 11 open for air displacement through passage 10and gap 23.

The forward vane 11 in front of the aileron 21 can be a part of andoperated with the vane l1 which is disposed at the forward end ofpassage 10 ahead of the rear flap 12, or that portion of vane 11controlling passage 10 ahead of the aileron can be a separate elementindependently controlled. While the aileron mounting is shown applied toa convertible wing of the type of Fig. 1 it is capable and intended forgeneral application to any and all forms of wings or lift surfaces, orcan be employed with a wing having a passageway and forward end openingandv closing means solely coextensive with the aileron or controlsurface, as will be obvious to those skilled in the art and contemplatedand included in the invention. Operating mechanism (notshown) of anydesired or familiar t pe can be employed forthe aileron 21, and7 theforward vane 11 can be operatively coupled with the aileron so as to beopened whenl the aileron is moved from then'ormalposition, or theaileron and vane can be independently operated or controlled. Further,where found expedient the vane l1 forward of thel aileron 21 can heeliminated to -leave the passage 10 which passes over aileron 21permanently open.

.A wing embodyin the invention and presenting a modified esign andarrangement of air displacement passage,isshown by Fig.

maarre t ofthe drawings. An upper airfoil A' is pro- 3110i a depth orthickness equal to the depth of the converted wing. A forward wing beamor-spar 32, in the form'of an I beam, is rovided in the deepforwardlsection 31 an the forward section is inclined on its under side from a.point adjacent beam 32, upwardly and rearwardly to'and joining theirsection 30. A rear or trailing edge section 33 is also formed on upperairfoil A', which section decreases in de th forwardly to and joinssection 30 of the airfoil. A series of ribs 34 are spaced at intervalsalong the span, transversely of airfoil A', and extending section' 33,across the space therebetween. A rear wing beam or spar 35 is-fixedacross the under sides or ribs 34 disposed below the thin section 30 andbetween the forward Aand rear sections 31 and 33, the ribs 34 beingformed with lightenin holes or air passages 15' therethrough 1n thespace betiween the forward and rear sections of the airfoil. A lateralcontrol surface or aileron 36 is pivotally mounted to and extendingrearwardly from the trailing edge of upper airfoil A', for operation inthe usual manner byv any suitable mechanism (not shown).

between forward section 31 and trailing' According to the form of theinvention i of Fig. d, the lower airfoil B' is formed of va forward flap37 and a rear flap 38 pivotally mounted on the rear wing beam 35 andextending forwardly and rearwardly therefrom, respectively. The forwardflap 37 extends forwardly to and in raised position joins with the lowerrear side of the thick forward section of upper airfoil A', and the rearflap 38 in raised position extends to and joins with thetrailing edgesection 33 of the upper airfoil, thus closing the space or airdisplacement passage 10' between the upper airfoils and these aps spacedbelow the thin section 30 thereof, and forming with the upper airfoil A'a single wing of relatively thick section t e. The raised position ofiiaps 3?-38 orming lower airfoil B' is shown by dotted lines in Fig. 4.In lowered position as shown in full lines in Fig. 4, the forward andrear ends of space 0r passage 10' are opened, and an upwardly,rearwardly and downwardly 4extending distendency of the air How to passthe inlet upper airfoil A',

-flight operation and use o without entry, but the lowered forward iiap37, togetherwith the usual increase in the `angle of attack of the wingwith the passage open causes entry and flow of air rearwardly throughthe displacement. A formV of operating mechanism is disclosed in Fig. 4,for simultaneously swinging flaps 37*- 38 upwardly to wing convert-V ingand passage closing position, or downwardly to passage opening position.A bell crank 40 is pivotally mounted in vertical positionin the forwardvthick section 31 of and its`horizontally disposed arm is pivotallyconnected by ade-- pending link 41 with the flap 37 adjacent the'leadingedge thereof, A vertically posed crank 'or control mast 42 is secured'extending upwardly into passage 10 from the lla 38 adjacent the leadingedge thereof, andJ a link 43 is pivotally connected between mast 42 andthe vertical'arm of bell crank 40. Thus, by rocking bell crank. 40forwardlythe flaps 37-38 taneously to passage closing, wing convertingposition, and by rocking the same rearwardly these flaps are.simultaneously low` ered' to passage ,openin position. The t-he wing ofFig. 4 is similar to that described with reference to Figs. 1 and'2. Forlow incidence high speed iiight, the flaps 37 and 38 forming lowerairfoil B-are raised to couvert the wing to a` single relatively thicksection type, and for high incidence, maximum lift operation theliapsare lowered to open pas? sage'lO for displacement of air rearwardly anddownwardly therethrough. A f f A modifiedv form of nose flap and anexternal rib member necessitated thereby, areV to include any and alllift surfaces or aero- ""wings indicated by the dotted lines in Fig. 4.

' By the invention an' airplane supporting surface or wing is providedin which high efficiency is obtained through an increase in the liftdeveloped at high angles of ilicidence while retaining in the wing the,desired-characteristic of high lift/drag value at vlow incidence throughIthe convertible features of the invention. Structurally the disclosedherewith are capable of low weight and high safety factor, and can bepractically manufactured and are readily inspected in use with resultingminimum ossibility of failure and llow costiof up' ecp. e-wingsconstructed with the dee leadingl edge section of the upper airfoil, as.shown in Fig. 4, due to the deep forward beam lend themselves tointernal truss ing as will be recognized by those skilled in this art.

In the appended claims'the term airplane wlng is employed in a broad,

generic sense dynamic elements, symmetrical or-non-'symmetrlcal in thebase section and in any cellule combinations thereof, having orembodying are raised simulthe general characteristics of lift through reaction of air thereon.

,No vclaim is herein made to the aileron 0r lateral control surfacemounting and arrangement disclosed in Fig. l1 o-th draw- '[0 ings anddescribed herein, as such aileron or control surface mounting andarrangement is disclosed and claimed in my pending application v'SerialN o. 343,225,.iiled-Februa 27, 1929, as a division of the prese'ntappll- 75 cation. 1 It is also evident that various other changes,modifications', substitutions and va riations, than those above referredto, might be resorted'to without departing from the so spiritand scopeof my invention,and hence `do no't wish or 'intend to limit myself tothe exact and specific disclosures hereof.V

Desiring to protect my invention in. the

lbroadest manner legally possible, what 1,8 5

claim is: 1. An airplane wing embodying supervposed airfoils' spacedapart to form an air displacement passage Itherebetween, means Aforclosing said passage to convert the airfoils to a single wing section ofsubstantially unbroken contour, and one of said airfoils of relativelythin section with respect to the other of said airfoils.

2. An airplane wing embodying superposed aifoils spa-ced apart to formanair displacement passage therebetween, means for closing said passage'to ponvert the airfoils to form a single wing section of substantiallyunbroken contour, and one of said airfoils of relatively thin section tosecure a maximum ldepth of air displacement pas sage without increase inthe total depth of the wng. yv l.

4. An ai" lane wing embodying superposed space 1Vairfoils to lform anair displacement passage therebetween, 4a series 115 of transverse ribsspaced at intervals along the span of the 'w1ng, between and connect-ling said airfoils, a forward'wing beam lin the upper airfoil, and a rearwing beam in the lower airfoil, said beams connected to 12,0

said ribs.

5. A n airplane wing embodying spacedl superposed airfoils forming anair displacement. passage therebetween, a series of 'transverseribsbetween and connecting ,said 1 25 airfoils. the upper of saidairfoils formed wardly extending leading edge sectionhav- 13 and theupper airfoil of relativelym0* ing substantial thickness, and a forwardbeam for the wing mounted in said leading' edge section across andconnecting said ribs.

6, An airplane wing embodying spaced superposed airfoils forming an airdisplacement passage therebetween, transverse ribs between andconnecting said airfoils at superposed airfoils forming Aan airdisplaceplacement Ament passage therebetween, vtransverse ribs betweenand connecting said 'airfoils at spaced intervals along the span, the'upper airfoil formedand delined by a-relatively thin covering secured toand over said ribs, said covering terminating in a downwardly extendngleading edge section having substantial thickness, the lower airfoil ofless chord than the upper airfoil, a vane pivoted-between and extendinglongitudinal of the -forward open end of the air displacement passa efor movement to position opening sai passage, and to position across andconnecting the upper and lower airfoil leading edges to close saidpassage, and a rear-flap pivotally mountd ,on and extending from thelower .airfoil for downward movement opening the rear end of saidpassage and for upward movement closing the passage and .connecting thelower airfoil with the trailing edge portion of the upper 'airfolin b dd 8. airplane. wind em o space superposed ,airfoils forning aniiiilgdisplacement passage therebetween, longitudinal beam members insaid airfoils, and a series of spaced transverse rib members disposed atintervals along the span of the wing between and connecting the airfoilsand said longitudinal beam members;

9. An airplane wing embodying spaced, superposed airfoils forming an airdisplacement passage therebetween, the upper airfoil including aforwardly located longitudinal beam, the lower airfoil including arearwardly located beam, and a series of transverse rib members spacedat intervals along the span between and connecting said airfoils, thelongitudinal beams of the upper and lower airfoil forming the forwardand rear longitudinal beams, respectively for the wing. I Y A Y 10. lnan airplane wing having an air disiassage therethrough, a lateralcontrol sur ace pivotally'mounted across the rear endof said passage forvertical swing- ,the upper surface of the wing, and tending to closesaid passage when raised, and extending below the lower surface of thewing and opening the passage when lowered.

11. In an airplane wing embodying spaced superposed airfoils forming anair displacement passage therebetween, a. vane pivotally mounted at theforward end of said passage for openingl and closing the same, said vanein closed position connecting the leading edges of said airfoils, a rearflap pivotally mounted on the lower airfoil in rearward continuationthereof for opening and closing the rear end of said passage, the reariiap terminating a distance inwardly from the wing tip, and a lateralcontrol surface pivotally mounted on and eX- tending rearwardly from thelower airfoil between the rear flap and the wing tip, and said lateralcontrol surface openable independently of th rear flap' and when swungto raised positions partially closing the passage adjacent thereto, andin lowered positions opening the same.

.12. ln an airplane wing having an air displacement passage therethroughdischarging adjacent the trailing edge of the wing, a lateral controlsurface for the wing operatively mounted at the discharge end of` saidpassage and extended beyond the wmg trailing edge.

13. In an airplane Wing having an air displacement passage therethroughdischarging adjacent the trailing edge of the wing, a lateral controlsurface for the wing pivotally mounted disposed at the discharge end ofthe passage, said control surface extending beyond the wing andpartially closing said passage when swung upwardly while opening thepassage when swung downwardly.

14. In an airplane wing having an air displacement passage therethrough,a, lateral control surface for the wing pivotally mounted at thedischarge end of such passage for vertical movements, said controlsurface extended beyond the trailing edge of the adjacent portion of thewing and partially closing said passage when swung upwardly, whileopening the passage when swung downwardly from upwardly swung position.o

15. ln. an` airplane wing embodymg spaced airfoils forming an airdisplacement passage therebetween, a rear flap pivotally mounted on thelower airfoil in rearward continuation thereof for opening and closingthe rear end of said passage, said rear dep terminating a distanceinwardly from the wing tip, and a control surface pivotally mounted andextending rearwardly from -the lower airfoil between the rear Hap and'the wing tip, said control surface partially closing the passage whenswung to raised ing movement, said surface extending above positions.

` 16. In an a' lane wing embodying s aced, superpose airfoils forming anair lfisplacement passage therebetween, a lateral control surface.mounted' to -the rear and substantially inthe lane of the lower airfoil,said control sur acein`maximum raised wing depressingposition e'xtendingupwardly across and partially closing said passage torestrictairdischarge from the passage and reduce the lift developed by the wing,and said control surface in lowered wing 'elevating positions openingsaid pas' sage to increase discharge of air 'from the PSSage the wing.

17. In an airplane wing having an air displacement 'passage extendingrearwardly therethrough, the

combination with a flap member for opening and closing the' dischargeend of the said passage, of a lateral control surface at the dischargeend of the paageextending; along a portionof the width 4of said mssage,said control surface in raised wing depressing positions extendingacross and restrictlng air discharge from said passage, and inloweredwing elevating positions opening the passage to increase airdischar e therefrom, the saidcontrol surface and ap member independentlyoperable. Y Y

18.111 n nirplnerwing, ma wing and increase the lift Vdeveloped by,

'dof October, 1926;

19;.In an airplane wing 4formed with an w air 'displacement passagetherein having its inlet through the lower surface of the wing adjacentthe Wing leading edge, a flap member normally closing said inlet saidmember swingable outwardly to 'position projected downwardly` from theunder'surfaceof the wing toV openthe passage inlet and force airtherethrough into Asaid passage, and -said said displacement passagethrough the upper'SurlaceV of thewing spaced forwardly from but adjacentto the trailing edge por,- tion .of the wing for discharging air fromthe displacement passage rearwrdly above said trailing edge portion Witmember incinlet opening position.

said ilapV 5o .I wing providedY with a discharge outlet from signed atIthaca, ANew York, this 16th day f RANDLPH

